Cellulose organic ester composition containing phenyl propionate



Patented Aug, 18 19 UNITED.- STATES,

oELLULosE ORGANIC ESTER COMPOSITION CONTAINING PHENYL PROPIONATE HenryB. Smith, Rochester, N. Y., assignor to Eastman Kodak Company,Rochester, N. Y., a corporation of New York N Drawing. Application JulySerial No. 735,829

, 7 Claims.

' This invention relates to compositions of matter in which celluloseorganic esters, such as cellulose acetate, are combined or mixed withother substances, such as a compatible plasticizer, with or without acommon solvent for both, and with or without other useful additionagents, so that the resulting product will have properties such as willmake the composition highly advantageous for use 'in the plastic andanalogous arts, such, for instance, as the manufacture of wrapping.sheetsor tissue, photographic film, molding compounds and products,artificial silk, varnishes or lacquers, coating compositions and thelike. J

One object of 'this invention is toproduce compositions of matter whichmay be made into permanently transparent, strong and flexible sheets orfilms of desired thinness which are substantially waterproof, are.unaffected'by ordinary photographic fluids and possess the desiredproperties of a support for sensitive photographic coatings. Anotherobject of my invention is to produce compositions of matter which arecapa ble of easy and convenient manipulation in the 5 plastic andanalogousjarts, such asjin the manufacture of sheets, film, artificialsilk filaments, varnishes, lacquers 'andthe' like, andjto producecompositions which will'not injure, or be injured by, the substances 'orsurfaces with which they are associated .during manufacture. Anotherobject of my inv'er'ition'isto produce compositions which-can be moldedat'ele'vated temperatures and high pressures to. produce plasticproducts having the desirable properties of. celluloid. Still anotherobject of my invention is to produce compositions of .mattercont'ainingcellulose acetate which have a high degree of flex-s ibility, softnessand pliability. Other objects will become apparent to those skilled theart to which this invention pertains.

While ce11u1o'se" acetate has been known for decades, it has also beenknown that to utilize it in the various plastic arts it is necessary tomix therewith various plasticizing or conditioning agents. Certain ofthese and other addition agents are also added for the purpose ofreducing the inflammability of the product. Plastic inducing agents,such as the higher alcohols and their esters, are sometimes also added.Similarly, addition compounds of various kinds have been employed toincrease flexibility, transparency, toughness, and other propertieswhich will enhance the value of the resulting product. Addition productsfor the same or similar purposes are also added to cellulose acetate toprepare it for use in the other plastic arts, such as in the'manufactureof lacquers, varnishes, artificial silk filaments, molded compounds, andthe like. While the plasticizers or other addition agents heretoforediscovered have had their 5 utility in the art, the increasing use towhich cellulose acetate has been put and the increasing number ofdesirable properties required of cellulose acetate for most purposeshave made the discovery of new and economical plasticizers or 1 otheraddition agents'a matter of considerable importance to the art. This hasbeen a problem of some difliculty, since many of the nitrocellulosesolvents are not solvents for cellulose acetate, and many substanceswhich act as plas- 15 ticiz ers for nitrocellulose are not compatible orat least not sufficiently compatible with cellulose acetate to be usedas plasticizers in cellulose acetate compositions. I I have discoveredthat valuable properties may 20 be'induced inand/or contributed tocompositions containing organic esters of cellulose, such as celluloseacetate, by adding thereto, as a plasticizing compound,phenylpropionate. The particularly useful properties which this compoundinduces in or contributes to cellulosic compositions containing it arehereinafter enumerated.

Phenyl propionate may be prepared as follows. 2 kg. (21 g. -moles) ofphenol and 2 kg. (22 g.- moles) of propionyl chloride are heatedtogether in a 5 liter flask on a steam bath for about four hours, oruntil hydrogen chloride is no longer evolved. The reaction mixture iswashedwith an equal quantity of water, and then with another equalportion of water containing 10 to 20 grams of sodium carbonate. Thecrude product is dried with anhydrous calcium chloride and distilledin". vacuo. Phenyl propionate boils at 96-98 C. at 9 mm. pressure. 7 V

'In order that those skilled in this art may better understand myinvention I would state, by way of illustration, that for themanufacture of photographic film base or other sheets my newcompositions of matter may be compounded as follows: 100 parts ofacetone-soluble cellulose acetate, 1. e., cellulose acetate containingfrom about 36% to 42% acetyl radical, approximately, is dissolved withstirring at atmospheric temperature in 300 to 500 parts, preferably 400parts, by weight, of acetone. To this solution may be added from 10 to50 parts by weight of phenyl propionate. Within the limits stated, theamount of plasticizer may be decreased or increased, depending uponwhether it is desired 5 to decrease or increase, respectively, theproperties which this plasticizer contributes to the finished product.The amount of solvent employed may also be increased or decreased,depending upon whether it is desired to have a more or less freelyflowing composition, respectively. V V I A composition of 'matterprepared as above described may be deposited upon any suitablefilm-forming surface and the acetone evaporated therefrom to form a filmor sheet, in a manner well known to those skilled in thear-t. A film soproduced has permanently brilliant transparency and low infiammability,burning no morereadily than ordinary newsprint. Films or, sheetsproduced in accordance with my invention are very tough and flexible.For instance.

films of cellulose acetate plasticized with from 10% to 50% of phenylpropionate (10 to 50 parts by weight per 100 parts by weight ofcellulose acetate) had aninitial flexibility from 100% to 300% greaterthan that of film containingno plasticizer. Furthermore, film soplasticized maintains fiexibility in a superior fashion. 'For instance,at 65 0., films containing from 10% to 50% of phenyl propionatemaintained flexibility for 150 .days, whereas an unplasticized filmbecame brittle in '30 days. indicates that films or sheetssoplasticizedwillwithstand ordinary "usageisatisiacto'rlly for many years.

Other similar solvents (instead of acetone) which are compatible'withthe cellulose acetate and my new plasticizers will also occur to thoseskilled in thisart, such as ethylene chloride- 35.

alcohol mixtures. In like manner these plasticizers may be compoundedwith other single organic esters of cellulose, such as cellulosepropionate, butyrate, 'stearate and the like, or with mixed organicesters, such as. cellulose acetostearate, cellulose 7 aceto-propionate,cellulose aceto-butyrate, cellulose aceto-lactate, celluloseaceto-tartrate or the like, a suitable solvent which will dissolve boththe cellulosic derivative and the plasticizer 'being employed, such, forinstance, as an'alkylene'chloride with'or without the addition ofalcohol. 7

Inasmuch :as my above-described compositions of matter -areusefu1 in theproductionof films and sheets, it will be apparent that my newplasticizers may also be-employed withadvantage in 'the other branchesof the plastic art. For instance, 'my novel plasticizers may be employedthe plasticizer is usually first put into solution in the cellulosederivative solution, and if nonsolventsi are added for the purpose ofcheapening the composition they are added only to such an extent as willnot precipitate the derivative from solution. Other uses within thescope .of

2,051,585 r V l my invention will also suggest themselves to thoseskilled in the art and are to be included within the scope of the claimsappended hereto.

Phenyl propionate may also be advantageously used as a plasticizer incellulose organic ester molding compositions. For instance, when about30% (30 parts by weight per parts of cellulose acetate) of phenylpropionate is "homogeneously mixed with cellulose acetate, the mixturemay be converted into a hard, transparent or translucent plastic productby molding at a temperature of -160 C. and a pressure of 2500 to 4000pounds per square inch for a period of from 2 to 5 minutes, in a manneralready known to those skilled in molding compounds of that nature.

tion to cellulose acetate of approximately 100% of phenyl propionate,quite unexpected compatibility of the plasticizer with the cellulose VMoreover, I have found that, upon the addiacetate exists and also that.quite unexpected flexibility, plasticity and clarityoithefinal product7 result. Contrary to experience in most cases where .such'alarge'proportionof plasticizer is stances be desirable.

WhatI claim as my invention and desire to be secured by Letters Patent01" the United States is:

l. A composition of matter comprising a"cel-' lulose organic acid esterand phenyl propionate.

2. A composition ot matter comprising cellulose acetate and phenylpropionate. i

3. .A composition of matter comprising 100 parts of cellulose acetateand from 5 to 100 parts, .by weightoi phenyl propionate.

4. A transparent, "flexible sheet comprising 100 parts of a celluloseorganic acid'ester and, as a plasticizer therefor, about 10 to 60 parts,by weight, of phenyl propionate.

5. A transparent, fiexible'sheet comprising 100 parts of celluloseacetate and, as a plasticizer therefor, about 10 to 60 parts, by weight,of phenyl propionate. H

6. A molding composition'adapted for moldme under elevated temperaturesand high pressures, comprising a cellulose organic acid ester and phenylpropionate.

'1. .A molding composition adapted for molding under elevatedtemperatures and'high pressures, comprising cellulose (acetate andphenyl propionate.

HENRY B. SMITH.

7 than 100% of the plastlcizer may in some in- V

